The present invention relates to a retaining ring having a layered composite powdered metal construction for use with a cylinder head gasket.
A cylinder head gasket bears a clamping load from a bolted connection of a cylinder head and an engine block and relies upon that load to provide a seal against the sealing elements of the gasket.
The gasket includes a combustion seal ring to prevent the leakage of combustion gases during engine operation. Several types of combustion seal rings are known. One type, known as a yieldable combustion seal ring, is essentially comprised of a wire having a generally circular cross-sectional area. A clamping force applied to such a ring is concentrated at the point of contact, deforming the ring's circumference to effectively seal out combustion gases. This type of seal ring, however, is subject to thermal crushing which results from plastic deformation which tends to occur under high temperature operation during the life of the ring.
Dual sealing systems are known. U.S. Pat. No. 4,188,037 to Abbes, et al. discloses the use of a spring seal in combination with an elastomeric ring. The seals are not utilized as a portion of a combustion seal for a cylinder head gasket. Further, U.S. Pat. No. 4,369,980 to Backlin, discloses a cylinder head gasket for an internal combustion engine having double metal wrapped hoops to provide a reinforced fire ring around the combustion chamber. This type of dual seal fire ring is still subject to leakage under certain circumstances.